1. Technical Field
The present invention relates to a roller burnishing tool device, especially to a roller burnishing tool device equipped with a tool diameter following mechanism.
2. Description of Background Art
A roller burnishing tool device is a device which presses a roller or rollers, while rotating the roller or the rollers, onto a workpiece, for example, onto an inner surface of a cylindrical hole of the workpiece, to plastically deform and finish the surface to be a mirror surface. The finishing by using the roller burnishing tool device is affected by a variation of the diameter of the hole to be processed or a difference of several tens of microns (μm) in setting a tool diameter. Note that, in this specification, the variation is a variation among hole diameters of holes of workpieces to be processed, or a variation among hole diameters at positions in a hole of a workpiece to be processed in the axial direction of the hole. Hereinafter, these two types of hole diameters are sometimes called as an inner diameter (of an inner surface of a workpiece) or a hole diameter (of a workpiece) without distinction. Therefore, there is known a roller burnishing tool device equipped with an adjustment spring mechanism and a displacement mechanism, which device is capable of automatically coping with the variation of a hole diameter (following a tool diameter) (for example, the patent literature 1).
The roller burnishing tool device described in the patent literature 1 is controlled by the adjustment spring mechanism so that a change of a rotational load torque acting on the displacement mechanism is kept in a prescribed set value. The displacement mechanism is equipped with a roller unit disposed between a shank and a driver. The driver is moved in an axial direction relative to the shank by the change of the rotational load torque by utilizing a feed mechanism with a feed angle and a planetary motion of flexible rollers of the roller unit. Thus the roller burnishing tool device is capable of coping with the variation.
Patent literature 1: Japanese Patent No. 3245638, B (paragraphs 0044 to 0054, FIG. 1, FIG. 3)